Weight Paint and deforming issue
I think everyone has his own way to rig, personally I would organize the armature this way: switch the direction of your hips bone and parent the thigh and the spine to it. Also, you will need to enable the Deform option of this bone. And, at last, you will have to switch to Weight Paint mode to make a lot of corrections, because it's currently not well weight painted: Keep your armature in Pose mode, then select your mesh and switch it to Weight Paint mode, then select each bone to see and correct its influence.